Haploid gametes (sperm and eggs) are generated by meiosis and are essential for sexual reproduction. In females, meiosis is highly error-prone as ~5-20% of a young, healthy woman’s eggs contain an abnormal number of chromosomes (aneuploid). Aneuploidy is the leading cause of infertility, miscarriage and, in the case of live birth, developmental disorders such as Down Syndrome. Little is known, however, about how meiosis in females is regulated and why it is so prone to chromosome segregation mistakes. Research in our group uses the mouse oocyte model to understand how signal transduction networks, specifically at the level of protein kinases and protein phosphatases, regulate female meiosis.